1. Field of the Invention
The present invention relates to a battery pack in which a protection circuit for controlling charging/discharging currents is mounted inside an exterior cover settled at an upper end of a unit cell.
2. Description of Related Art
In this type of battery pack, it is becoming mainstream that a circuit board and a protective device, or positive and negative leads or other electrical components are intensively placed on a sealed surface side of the unit cell. The electrical connection structure between the unit cell and the circuit board for such a kind of battery pack has been proposed in several forms to substitute for spot welding. For instance, in a battery pack disclosed in JP 2006-114468 A, positive and negative terminals of the unit cell and positive and negative terminals of the circuit board are electrically connected to each other by gold-plated, compression coil-type connectors or plate spring-type connectors. A connection structure using compression coil-type connectors is disclosed also in JP 2003-197270 A.